The present application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 61/824,235, filed on May 16, 2013, and entitled “Semiconductor Trenches Having Thick Bottom Dielectrics Suitable for Field Plates.” The disclosure of the above application is hereby incorporated fully by reference into the present application.
Power semiconductor devices, such as metal-oxide semiconductor field-effect transistors (MOSFET), are widely used in a variety of electronic devices and systems. Examples of these devices and systems include switches, DC to DC converters, and power supplies. In power devices, improving performance characteristics such as breakdown voltage, ON resistance (Rdson), and output capacitance are increasingly important. For example, it is desirable to lower Rdson, increase breakdown voltage, and decrease output capacitance, particularly using methods which do not add to the thermal budget for fabrication of semiconductor devices.
Conventional methods traditionally optimize one performance characteristic at the expense of another. For example, a semiconductor device may reduce Rdson at the expense of lowering the breakdown voltage of the device. As such, there is a need for a structure and method for power MOSFETs that can overcome the deficiencies in the art.